## mark a section (Learn more)

require 'matrix' # # Extensions to built-in Ruby classes # class Matrix def self.rotation(angle) cos_a, sin_a = Math.cos(angle), Math.sin(angle) Matrix[ [cos_a, -sin_a], [sin_a, cos_a] ] end def self.reflection; Matrix[ [1,0], [0, -1] ]; end end class Array def to_s return self.inspect if not self[0].is_a? Float inject("[") {|p,q| p += sprintf(" %.1f",q)} + "]" end end class Vector def rotateBy radians; Matrix.rotation(radians) * self; end def reflection; Vector[@elements[X], -@elements[Y]]; end def reflectBy radians; reflection.rotateBy(radians); end def angle; Math.atan2(@elements[Y], @elements[X]); end def ratio; @elements[Y] / @elements[X]; end def area; @elements.inject(4) {|x,y| x*y}; end def within?(size) each2(size) { |self_i, size_i| return false if self_i.abs > size_i } true end def to_s; to_a.to_s; end end BOUNDS = Vector[1500.0, 1250.0] SCREEN_SIZE = Vector[700.0, 500.0] SCREEN_ORIGIN = SCREEN_SIZE * 0.5 SHELL_SIZE = Vector[2.0,2.0] TANK_SIZE = Vector[10.0,15.0] MUZZLE_SIZE = Vector[25.0,0.0] Shoes.app do b = Vector[-500.0, 250.0] para b.to_s end

This paste will be private.